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Re: Collection / Grammar Issue

From: Sandro Hawke <sandro@w3.org>
Date: Wed, 15 May 2013 22:57:37 -0400
Message-ID: <51944B21.2030407@w3.org>
To: Gavin Carothers <gavin@carothers.name>
CC: Eric Prud'hommeaux <eric@w3.org>, Alex Milowski <alex@milowski.com>, "public-rdf-comments@w3.org" <public-rdf-comments@w3.org>
On 05/15/2013 10:44 PM, Gavin Carothers wrote:
> I have no idea. We're the ones who wrote the example Sandro ;) ... eric?
>

Oh.   Then lets just fix the example, adding a ":a :b" in front of the 
list, yes?

        - s

> RDF collections can be nested and can involve other syntactic forms:
>
> @prefix : <http://example.org/stuff/1.0/> .
> (1 [:p :q] ( 2 ) ) .
>
> is syntactic sugar for:
>
> @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
>      _:b0  rdf:first  1 ;
>            rdf:rest   _:b1 .
>      _:b1  rdf:first  _:b2 .
>      _:b2  :p         :q .
>      _:b1  rdf:rest   _:b3 .
>      _:b3  rdf:first  _:b4 .
>      _:b4  rdf:first  2 ;
>            rdf:rest   rdf:nil .
>      _:b3  rdf:rest   rdf:nil .
>
>
>
> On Wed, May 15, 2013 at 7:34 PM, Sandro Hawke <sandro@w3.org 
> <mailto:sandro@w3.org>> wrote:
>
>     On 05/15/2013 07:41 PM, Alex Milowski wrote:
>>     I ran across a problem while implementing a Turtle parser.
>>
>>     In section 3 of [1], the 7th example is:
>>
>>     @prefix : <http://example.org/stuff/1.0/> .
>>     (1 [:p :q] ( 2 ) ) .
>>
>
>     (unofficial reply, trying to clarify)
>
>     Why would you want a turtle file that's just a list?   How would
>     you use that?
>
>             -- Sandro
>
>
>>     The production for triples in section 6.5 is:
>>
>>     [6]triples::=subject predicateObjectList | blankNodePropertyList
>>     predicateObjectList?
>>     [7]predicateObjectList::=verb objectList (';' (verb objectList)?)*
>>     [10]subject::=iri | BlankNode | collection
>>
>>     According to these productions, the example is invalid.  The
>>     subject reduces to the collection and must be followed by a verb.
>>      Yet, the example does not have a following predicate object list.
>>
>>     If this is truly suppose to be valid, I think the productions
>>     need to be:
>>
>>        triples::=subject predicateObjectList |
>>                             collection predicateObjectList? |
>>                             blankNodePropertyList predicateObjectList?
>>        subject ::= iri | BlankNode
>>
>>     BTW, it would be a wonderful editorial change to number the
>>     examples.
>>
>>     [1] http://www.w3.org/TR/2013/CR-turtle-20130219/
>>
>>     -- 
>>     --Alex Milowski
>>     "The excellence of grammar as a guide is proportional to the
>>     paucity of the
>>     inflexions, i.e. to the degree of analysis effected by the language
>>     considered."
>>
>>     Bertrand Russell in a footnote of Principles of Mathematics
>
>
Received on Thursday, 16 May 2013 02:57:49 UTC

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